the seven year war (known as the French Indian war in N. America). He may or may not obtain a commission as an officer from the British army, but he definitely fought on the Anglo side. In any army, there are commissioned officers and non-commissioned soldiers and the vast majority consists of non-commissioned soldiers.

In fact, obtaining a commission as an officer is a tricky business. For example, during the American civil war, one can be a Major General of the volunteers or be commissioned as a Major General in the regular army. The latter has far more prestige and authority than the former.